Radio communication terminal and control method therefor

ABSTRACT

In a radio communication terminal, a microprocessor determines a mode selected by user manipulation of a key input portion. The microprocessor turns on a backlight of a display with the backlight in accordance with the determined mode, controls the time period of a bright display mode, and turns the backlight off after the lapse of the period to switch the bright display mode to a dark display mode. The ON time period in the bright display mode is set longer in another mode than in a normal mode. The backlight ON time is optimally controlled in correspondence with a mode selected by the user, thereby improving the operability and prolonging the service life of the battery.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based upon and claims the benefit of priorityfrom the prior Japanese Patent Application No. 11-370381, filed Dec. 27,1999, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a radio communication terminalhaving a display such as an LCD (Liquid Crystal Display) with abacklight and a control method therefor and, more particularly, to aradio communication terminal whose operability is improved by optimallycontrolling the backlight ON time in correspondence with a mode selectedby the user, and a control method therefor.

[0003] In general, a radio communication terminal such as a mobile phoneor cellular phone comprises a display for displaying various pieces ofinformation to the user. As the display, an LCD with a backlight is usedto meet demands for downsizing a radio communication terminal of thistype and cope with various use environments.

[0004] To prevent consumption of the battery, the LCD with a backlightis controlled to keep the backlight on for a predetermined period, e.g.,10 sec after user manipulation, e.g., when the user presses any key, andautomatically turn the backlight off when no new user manipulation isdone within the predetermined period.

[0005] Recent radio communication terminals such as mobile phones orcellular phones have remarkably been developed to realize variousfunctions.

[0006] These functions include a service of accessing a remote serverwhich stores data, and extracting desired contents stored in the storageserver, like WAP (Wireless Application Protocol) service. When the useris to receive this service and enters this service mode, keymanipulation or the like may become unnecessary for a predeterminedtime.

[0007] Also in a mail creation mode or mail browsing mode for mailcommunication frequently used recently, user manipulation such as pressof a key may not be done for a predetermined time.

[0008] However, in a radio communication terminal having a conventionalLCD with a backlight, the backlight is turned off if no new usermanipulation is done within a predetermined period after usermanipulation, as described above. When the user selects the informationextraction mode such as the WAP service, mail creation mode, mailbrowsing mode, or the like, the backlight is often automatically turnedoff against the user's will. In this case, the user must performredundant manipulation of, e.g., manipulating any key in order to turnthe backlight on again.

[0009] If the user erroneously manipulates the key, the mode selected bythe user may be switched to another unintentional mode, or the user mayperform erroneous character input.

[0010] To solve this problem, the backlight ON time of the LCD with abacklight may be prolonged. However, simply prolonging the backlight ONtime fails to achieve the original purpose of preventing consumption ofthe battery.

BRIEF SUMMARY OF THE INVENTION

[0011] It is an object of the present invention to provide a radiocommunication terminal for optimally controlling the backlight ON timein accordance with a function selected by the user, thereby improvingthe operability and prolonging the service life of a battery, and acontrol method therefor.

[0012] According to the present invention, there is provided a radiocommunication terminal having

[0013] display means for displaying information to a user, and

[0014] backlight means for illuminating the display means with a lightbeam in correspondence with user manipulation, thereby improvingvisibility, comprising

[0015] determination means for determining a function selected by theuser, and

[0016] control means for changing an ON time of the backlight meansafter the user manipulation in correspondence with the functiondetermined by the determination means.

[0017] The aspect defined in claim 2 according to the aspect defined inclaim 1 is characterized in that when new user manipulation is donewithin the ON time, the backlight means updates the ON time.

[0018] The aspect defined in claim 3 according to the aspect defined inclaim 1 is characterized in that when an information reception mode viaa radio channel is selected, the control means prolongs the ON time.

[0019] The aspect defined in claim 4 according to the aspect defined inclaim 1 is characterized in that when a mail creation mode is selected,the control means prolongs the ON time.

[0020] The aspect defined in claim 5 according to the aspect defined inclaim 1 is characterized in that when a mail browsing mode is selected,the control means prolongs the ON time.

[0021] The aspect defined in claim 6 is characterized by a controlmethod for a radio communication terminal having display means fordisplaying information to a user, and backlight means for illuminatingthe display means with a light beam in correspondence with usermanipulation, thereby improving visibility, comprising determining afunction selected by the user, and changing an ON time of the backlightmeans after the user manipulation in correspondence with the determinedfunction.

[0022] The aspect defined in claim 7 according to the aspect defined inclaim 6 is characterized in that when new user manipulation is donewithin the ON time of the backlight means, the ON time is updated.

[0023] The aspect defined in claim 8 according to the aspect defined inclaim 6 is characterized in that when any one of an informationreception mode via a radio channel, mail creation mode, and mailbrowsing mode is selected, the ON time is prolonged in correspondencewith the selected mode.

[0024] Additional objects and advantages of the invention will be setforth in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention may be realized and obtained bymeans of the instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0025] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate presently preferredembodiments of the invention, and together with the general descriptiongiven above and the detailed description of the preferred embodimentsgiven below, serve to explain the principles of the invention.

[0026]FIG. 1 is a block diagram schematically showing the circuitarrangement of a mobile phone or cellular phone as a radio communicationterminal according to an embodiment of the present invention;

[0027]FIG. 2 is a block diagram showing a whole system for explainingthe WAP (Wireless Application Protocol) service realized by the mobilephone shown in FIG. 1;

[0028]FIG. 3 is a flow chart showing processing of controlling ONoperation of the backlight of a display with a backlight in themicroprocessor of the mobile phone shown in FIG. 1; and

[0029]FIG. 4 is a flow chart showing another processing of controllingON operation of the backlight of the display with a backlight in themicroprocessor of the mobile phone shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0030] An embodiment of a radio communication terminal and a controlmethod therefor according to the present invention will be described indetail below with reference to the several views of the accompanyingdrawing.

[0031]FIG. 1 is a block diagram showing an embodiment of a mobile phoneor cellular phone to which a radio communication terminal and a controlmethod therefor according to the present invention are applied.

[0032] In FIG. 1, a mobile or cellular phone 10 of this embodimentadopts a CDMA (Code Division Multiple Access) method. The mobile orcellular phone 10 comprises a battery 11 serving as a power supply, apower supply circuit 12, an A/D converter 13, a memory 14, a display 15with a backlight, a key input portion 16, a microprocessor 17, aprocessing circuit 18 for processing a CDMA signal, a radio device 19,an antenna 20, a vocoder 21, an A/D converter 22, a microphone 23, a D/Aconverter 24, a loudspeaker 25, and a sounder 26.

[0033] The battery 11 is formed from a chargeable secondary battery. Anoutput from the battery 11 is supplied to the power supply circuit 12,which supplies a power supply voltage Vcc to each portion of the mobileor cellular phone 10. In addition, an output from the battery 11 isA/D-converted by the A/D converter 13, and supplied to themicroprocessor 17.

[0034] The memory 14 stores various pieces of information of the mobileor cellular phone 10, control programs for the microprocessor 17, andthe like. The display 15 is made up of an LCD (Liquid Crystal Display)151, and a backlight 152 for improving the visibility of the LCD 151. Aswill be described later, ON operation of the backlight 152 iscontrolled. The LCD 151 displays information in a dark display mode whenthe backlight 152 is not turned on, and displays information in a brightdisplay mode when the backlight is turned on. In the dark display mode,a light beam outside the LCD 151 is reflected by the LCD 151, and theuser recognizes a dark image. In the bright display mode, the LCD 151 isilluminated by a light beam mainly from the backlight, and an image isdisplayed bright. The key input portion 16 has a plurality of keyscontaining a dial key. User manipulation to the mobile or cellular phone10 is done via the key input portion 16.

[0035] The microprocessor 17 integrally controls the whole operation ofthe mobile or cellular phone 10. ON control of the backlight 152, whichis a characteristic feature of the embodiment, is also executed underthe control of the microprocessor 17.

[0036] The CDMA (Code Division Multiple Access) signal processingcircuit 18 processes a CDMA signal when the mobile or cellular phone 10communicates by radio with a public base station (not shown). Atransmission signal from the microprocessor 17 is converted into a CDMAsignal by the CDMA signal processing circuit 18, and the CDMA signal istransmitted to the public base station via the radio device 19 andantenna 20. A reception signal from the public base station is receivedas a CDMA signal via the antenna 20 and radio device 19, and convertedinto a digital audio signal by the CDMA signal processing circuit 18.The digital audio signal is input to the microprocessor 17.

[0037] The microphone 23 and loudspeaker 25 constitute the handset ofthe mobile or cellular phone 10. Voice input from the microphone 23 isA/D-converted by the A/D converter, the converted digital signal isencoded by the vocoder or voice coder 21, and the encoded digital signalis input to the microprocessor 17. The encoded digital signal from themicroprocessor 17 is input to the CDMA signal processing circuit 18where the digital signal is converted into a CDMA signal. The CDMAsignal is transmitted as a radio signal to the public base station viathe radio device 19 and antenna 20.

[0038] An audio signal received via the antenna 20 and radio device 19is input to the CDMA signal processing circuit 18 where the CDMA signalis converted into an encoded digital audio signal. The encoded digitalaudio signal is input to the microprocessor 17. The encoded digitalaudio signal from the microprocessor 17 is decoded into an audio digitalsignal by the vocoder 21, and the audio digital signal is converted intoan analog signal by the D/A converter 24. The analog signal is suppliedto the loudspeaker 25, which outputs it as voice.

[0039] The sounder 26 outputs a ringing tone in order to inform the userof termination in terminating operation of the mobile or cellular phone10.

[0040] The mobile or cellular phone 10 according to the embodiment ofthe present invention shown in FIG. 1 can realize various functions byselecting speech modes in which speech is made using the mobile orcellular phone 10, i.e., (1) a WAP service mode, (2) a mail creationmode, (3) a mail browsing mode, or the like by user manipulation via thekey input portion 16 in addition to a normal mode. The ON time of thebacklight 152 of the display 15 is optimally controlled in accordancewith a function, i.e., mode selected by user manipulation. This improvesthe operability of the mobile or cellular phone 10 and minimizesconsumption of the battery 11.

[0041] More specifically, in the mobile or cellular phone 10 accordingto the embodiment of the present invention, a function selected by usermanipulation of the key input portion 16 is determined by themicroprocessor 17, which variably controls the ON time of the backlight152 of the backlight-attached display 15 in correspondence with thedetermined function, as will be described later. That is, themicroprocessor 17 sets in accordance with user manipulation a periodduring which the display 15 displays information in a bright mode, andafter the time period elapses, controls the display 15 to displayinformation in a dark display mode in order to minimize consumption ofthe battery 11.

[0042]FIG. 2 is a block diagram showing a whole system for explainingthe WAP service realized using the mobile or cellular phone 10 shown inFIG. 1.

[0043] The mobile or cellular phone 10 shown in FIG. 1 is connected byradio to a public base station 30 distributed to each location. A speechfunction of making speech using the mobile or cellular phone 10, andvarious communication functions other than the speech function can berealized.

[0044] The public base station 30 is connected to a circuit switchingnetwork 40 having a packet switching function. The circuit switchingnetwork 40 is connected via a gateway 50 to the Internet 60 and astorage server 70 for realizing the WAP service. The storage server 70is connected to the Internet 60, which is connected to a personalcomputer 80.

[0045] In the WAP service realized using the mobile or cellular phone10, the mobile or cellular phone 10 accesses the storage server 70 viathe public base station 30, circuit switching network 40, and gateway50. Desired information is extracted from information stored in thestorage server 70, and supplied to the mobile or cellular phone 10. Theinformation is displayed on the display 15 of the mobile or cellularphone 10, thereby realizing the WAP service.

[0046] On the display 15 of the mobile or cellular phone 10 shown inFIG. 1, the backlight 152 is generally kept off, and the display 15 isdriven in a dark display mode in order to prevent consumption of thebattery 11. Only when any key of the key input portion 16 is pressed tosupply a user input, the backlight 152 of the backlight-attached display15 is turned on to drive the display 15 in a bright display mode. If nonew user manipulation of pressing any key of the key input portion 16 isdone within a predetermined period, e.g., 10 sec in this bright displaymode, the backlight 152 is automatically turned off to return thedisplay 15 to the dark display mode. The backlight-attached display 15is controlled by the microprocessor 17 so as to switch the display 15from the bright display mode to the dark display mode.

[0047] However, when the user is to receive the WAP (WirelessApplication Protocol) service as described with reference to FIG. 2, asituation in which no key manipulation is done within the predeterminedtime period during which the display 15 is maintained in the bright modeoccurs at a high probability in consideration of a period required toestablish communication between the mobile or cellular phone 10 and thestorage server 70, and a subsequent communication time.

[0048] In this case, the backlight 152 of the display 15 isautomatically turned off to switch the display 15 to the dark displaymode. To confirm information displayed on the display 15 on the basis ofthe WAP service in, e.g., a dark place, the user must manipulate any keyof the key input portion 16 in order to turn the backlight 152 on againand set the bright display mode again.

[0049] At this time, if a key which does not influence the WAP serviceexists, the user can press this key to turn the backlight 152 on again,thereby setting the bright display mode without influencing the WAPservice. If, however, the user erroneously presses a key whichinfluences the WAP service, the display 15 may switch to another modenot intended by the user only to execute erroneous character input.

[0050] In addition, redundant key manipulation is done every time thebacklight 152 must be turned on again, i.e., the display 15 is displayedin the bright display mode. This is cumbersome and undesirable in termsof user operability.

[0051] To solve this, when the WAP service mode is selected in themobile or cellular phone 10 of this embodiment, the time period duringwhich the backlight 152 of the backlight-attached display 15 is turnedon to maintain the bright display mode (corresponding to an automaticOFF period after which the backlight 152 is automatically turned off ifno user manipulation is done within this time period) is prolonged underthe control of the microprocessor 17.

[0052]FIG. 3 is a flow chart showing processing of controlling ONoperation of the backlight 152 of the backlight-attached display 15 inthe microprocessor 17 of the mobile or cellular phone 10 shown in FIG.1.

[0053] In FIG. 3, if the backlight 152 of the display 15 is in the OFFstate (dark display mode) (step 101), the microprocessor 17 monitors akey input from the key input portion 16 (step 102). If no key input issupplied from the key input portion 16 (NO in step 102), themicroprocessor 17 returns to step 102 to keep monitoring a key inputfrom the key input portion 16. If any key of the key input portion 16 ispressed, and the microprocessor 17 determines that a key input issupplied (YES in step 102), the microprocessor 17 checks whether the WAPmode is selected (step 103).

[0054] If the microprocessor 17 determines that the WAP mode is notselected (NO in step 103), it controls ON operation of the backlight ina normal mode, i.e., conversation mode. If no input is supplied in thebright display mode, and the automatic OFF period elapses, the backlightis turned off to return the display 15 to the dark display mode.

[0055] More specifically, in a normal mode, the microprocessor 17 setsthe time period during which the backlight 152 of the display 15 is kepton, to a predetermined initial value t0 (step 108), and turns thebacklight 152 on to set the bright display mode (step 109). If any keyof the key input portion 16 is pressed to supply a key input within thetime period of the initial value t0 after the backlight 152 is turned on(YES in step 110), the microprocessor 17 returns to step 109, updatesthe time period during which the backlight 152 is kept on (period of thebright display mode), and keeps the backlight 152 on.

[0056] However, if no key of the key input portion 16 is pressed withinthe time period of the initial value t0, and the microprocessor 17determines in step 110 that no new key input is supplied within the timeperiod t0 (NO in step 110), the backlight 152 is automatically turnedoff, and the display 15 returns to the dark display mode (step 101) inwhich the backlight 152 of the display 15 is turned off.

[0057] To the contrary, if the microprocessor 17 determines in step 103that the WAP mode is selected (YES in step 103), it prolongs the timeperiod during which the backlight 152 of the display 15 is kept on, to aprolonged time period Text, and controls ON operation of the backlighton the basis of the prolonged time period Text.

[0058] Whether to prolong the time period during which the backlight 152is kept on is realized by the user by setting in the mobile or cellularphone 10 ON time prolongation of the backlight 152 which selects to keepthe backlight 152 on during at least the prolonged time period Text inmanipulating the mobile or cellular phone 10 by the user and operatingthe mobile or cellular phone 10 in the WAP mode. That is, when the usersets ON time prolongation of the backlight by his manipulation inadvance to the time period Text prolonged from the time period (periodof the bright display mode) during which the backlight 152 is kept on,the function of prolonging the ON time period of the backlight 152 isexecuted. To the contrary, when the user disables in advance thebacklight ON prolongation setting, the function of prolonging the ONtime period of the backlight 152 is not executed, and ON operation ofthe backlight is controlled in a normal mode in which the backlight isturned off after the time period t0.

[0059] If the microprocessor 17 determines in step 103 that the WAP modeis selected (YES in step 103), it checks whether the backlight ONprolongation setting is enabled (step 104). If the microprocessor 17determines that the backlight ON prolongation setting is disabled (NO instep 104), it shifts to step 108 to control ON operation of thebacklight in the above-mentioned normal mode.

[0060] If the microprocessor 17 determines in step 104 that thebacklight ON prolongation setting is enabled (YES in step 104), it setsthe ON time of the backlight 152 of the display 15 to the prolonged timeperiod Text (>t0) (step 105), and keeps the backlight 152 on (step 106).

[0061] If any key of the key input portion 16 is pressed to supply a keyinput within the prolonged time period Text after the backlight 152 isturned on (YES in step 107), the microprocessor 17 returns to step 106,updates the ON time of the backlight 152, and keeps the backlight 152on.

[0062] If, however, no key of the key input portion 16 is pressed withinthe prolonged time period Text, and the microprocessor 17 determines instep 107 that no new key input is supplied within the prolonged timeperiod Text (NO in step 107), the backlight 152 is automatically turnedoff, the backlight 152 of the display 15 changes to the OFF state, andthe display 15 returns to the dark display mode (step 101).

[0063] According to the embodiment of the mobile or cellular phone inthe present invention, when the WAP mode is selected, the ON time periodof the backlight 152 of the display 15 is prolonged from the initialvalue t0 to the prolonged time period Text. If the prolonged time periodText is set to a time, e.g., 30 sec enough to receive the WAP service, asituation in which the backlight 152 of the display 15 is automaticallyturned off during the WAP service can be prevented as much as possible.As a result, user manipulation of performing redundant key operation inorder to turn the backlight 152 on again can be eliminated to greatlyimprove the operability of the mobile or cellular phone.

[0064] In the above embodiment, the ON time period of the backlight 152of the display 15 is prolonged from the initial value t0 to theprolonged time period Text when the WAP mode is selected. Also, the ONtime period of the backlight 152 of the display 15 may be prolonged whenanother function which requires prolongation of the ON time period ofthe backlight is selected, and the mobile or cellular phone ismanipulated in another mode.

[0065] Also, a situation in which no key manipulation of the key inputportion 16 is done within a predetermined time period may occur inanother mode, e.g., a mail creation mode in which mail is created in amail communication function of sending/receiving e-mail, or a mailbrowsing mode in which mail is browsed. Also when the mail creation modeor mail browsing mode is selected, the ON time period of the backlight152 of the display 15 is prolonged. In this case, the same effect ofeliminating any redundant key manipulation of turning the backlight 152on again can be expected.

[0066]FIG. 4 is a flow chart showing another processing of controllingON operation of the backlight 152 of the display 15 in themicroprocessor 17 of the mobile or cellular phone 10 shown in FIG. 1.

[0067] In ON control processing of the backlight 152 of the display 15shown in FIG. 4, the microprocessor 17 controls the backlight 152 so asto prolong the ON time period (period of the bright display mode) of thebacklight 152 of the display 15 not only when the WAP mode is selectedbut also when the mail creation/browsing mode is selected.

[0068] In FIG. 4, if the backlight 152 of the display 15 is in the OFFstate (step 121), the microprocessor 17 monitors a key input from thekey input portion 16 (step 122). If no key input is supplied from thekey input portion 16 (NO in step 122), the microprocessor 17 returns tostep 122 to keep monitoring any key input from the key input portion 16.If any key of the key input portion 16 is pressed, and themicroprocessor 17 determines that a key input is supplied (YES in step122), the microprocessor 17 checks whether the WAP mode is selected(step 123).

[0069] If the microprocessor 17 determines that the WAP mode is selected(YES in step 123), it sets the ON time of the backlight 152 of thedisplay 15 to a prolonged time period Text1 (>t0) (step 124). Thebacklight 152 is turned on to display information on the display 15 inthe bright display mode (step 125). If any key of the key input portion16 is pressed to supply a key input within the prolonged time periodText1 after the backlight 152 is turned on (YES in step 126), themicroprocessor 17 returns to step 125, updates the ON time of thebacklight 152, and keeps the backlight 152 on (bright display mode).

[0070] If, however, no key of the key input portion 16 is pressed withinthe prolonged time period Text1, and the microprocessor 17 determines instep 126 that no new key input is supplied within the prolonged timeperiod Text1 (NO in step 126), the backlight 152 is automatically turnedoff, and the display 15 returns to the OFF state of the backlight 152 ofthe display 15, i.e., to the dark display mode (step 121).

[0071] If the microprocessor 17 determines in step 123 that no WAP modeis selected (NO in step 123), it checks whether the mailcreation/browsing mode is selected (step 127).

[0072] If the microprocessor 17 determines that the mailcreation/browsing mode is selected (YES in step 127), it sets the ONtime of the backlight 152 of the display 15 to a prolonged time periodText2 (>t0) (step 128), and turns the backlight 152 on (step 129).

[0073] In this case, the prolonged time period Text2 is set to a valueoptimal for the manipulation status in consideration of the manipulationstatus upon selecting the mail creation/browsing mode. The prolongedtime period Text2 may be set to the same value as the prolonged timeperiod Text1 upon selecting the above-mentioned WAP mode.

[0074] If the microprocessor 17 turns on the backlight 152 of thedisplay 15 in step 129, it checks whether any key of the key inputportion 16 is pressed to supply a key input within the prolonged timeperiod Text2 after the backlight 152 is turned on (step 130). If themicroprocessor 17 determines that a new key input is supplied within thetime period Text2 (YES in step 130), it returns to step 129, updates theON time of the backlight 152, keeps the backlight 152 on, and maintainsthe bright display mode.

[0075] If no key of the key input portion 16 is pressed within theprolonged time period Text2, and the microprocessor 17 determines instep 130 that no new key input is supplied within the time period Text2(NO in step 130), the backlight 152 is automatically turned off toreturn to the OFF state of the backlight 152 of the display 15, i.e., tothe dark display mode (step 121).

[0076] If the microprocessor 17 determines in step 127 that the mailcreation/browsing mode is not selected (NO in step 127), themicroprocessor 17 controls ON operation of the backlight in a normalmode.

[0077] More specifically, the microprocessor 17 sets the ON time of thebacklight 152 of the display 15 to the predetermined initial value t0(step 131), and turns the backlight 152 on (step 132).

[0078] If any key of the key input portion 16 is pressed to supply a keyinput within the time period of the initial value t0 after the backlight152 is turned on (YES in step 133), the microprocessor 17 returns tostep 132, updates the ON time period of the backlight 152, keeps on thebacklight 152, and maintains the bright display mode.

[0079] If no key of the key input portion 16 is pressed within the timeperiod of the initial value t0, and the microprocessor 17 determines instep 133 that no new key input is supplied within the time period t0 (NOin step 133), the backlight 152 is automatically turned off, and thedisplay 15 returns to the OFF state of the backlight 152 of the display15, i.e., to the dark display mode (step 121).

[0080] Note that in this embodiment, the ON time of the backlight 152 ofthe backlight-attached display 15 is automatically prolonged to the timeperiod Text1 when the WAP mode is selected, and to the time period Text2when the mail creation/browsing mode is selected. Alternatively, whetherto enable/disable the backlight ON prolongation setting may be set inadvance in ON control processing shown in FIG. 3 individually for theWAP mode and mail creation/browsing mode, and only when the backlight ONprolongation setting is enabled, the ON time of the backlight 152 of thedisplay 15 may be prolonged to the prolonged time T01 or T02.

[0081] As has been described above, according to the present invention,in a control method for a radio communication terminal having a displaymeans for displaying information to the user and a backlight means whichis turned on for a predetermined time in accordance with usermanipulation to improve the visibility of the display means, a functionselected by the user is determined, and the ON time of the backlightmeans after the user manipulation is changed in correspondence with thedetermined function. This produces the effects of realizing optimalbacklight ON control in correspondence with a function selected by theuser, greatly improving the operability of the radio communicationterminal, and reducing consumption of the battery as much as possible.

[0082] Additional advantages and modifications will readily occur tothose skilled in the art. Therefore, the invention in its broaderaspects is not limited to the specific details and representativeembodiments shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general inventive concept as defined by the appended claims andtheir equivalents.

What is claimed is:
 1. A radio communication terminal comprising: inputmeans for inputting a user instruction for setting said radiocommunication terminal to either one of first and second modes; displaymeans for displaying information corresponding to input of the userinstruction, said display means displaying information at selectivefirst brightness and second display brightness lower than the firstdisplay brightness; setting means for setting said radio communicationterminal to either one of the first and second modes in accordance withthe input to said input means, and outputting a mode setting output; andcontrol means for controlling said display means, said control meanscausing said display means in the first mode to display information atthe first display brightness during a first time period and at thesecond display brightness after a lapse of the first time period, andcausing said display means in the second mode to display information atthe first display brightness during a second time period longer than thefirst time period and at the second display brightness after a lapse ofthe second time period.
 2. A terminal according to claim 1 , whereinsaid display means includes a display for displaying information visibleat the second display brightness, and illumination means forilluminating said display with a light beam to display information onsaid display at the first display brightness, and said control meanssets the first and second time periods in accordance with one set mode,and turns said illumination means on for either one of the set first andsecond time periods.
 3. A terminal according to claim 1 , wherein thefirst mode corresponds to a normal mode in which speech is made usingsaid radio communication terminal, and the second mode corresponds to aninformation reception mode in which data is received via a radiochannel, and said control means sets the second time period when theinformation reception mode corresponding to the second mode is selected.4. A terminal according to claim 1 , wherein the first mode correspondsto a normal mode in which speech is made using said radio communicationterminal, and the second mode corresponds to a mail creation mode inwhich mail is created via said input means, and said control means setsthe second time period when an information reception mode correspondingto the mail creation mode is selected.
 5. A terminal according to claim1 , wherein the first mode corresponds to a normal mode in which speechis made using said radio communication terminal, and the second modecorresponds to a mail browsing mode in which mail is browsed via saidinput means, and said control means sets the second time period when aninformation reception mode corresponding to the mail browsing mode isselected.
 6. A terminal according to claim 1 , wherein said controlmeans includes update means for, when a new user input is suppliedduring either one of the first and second time periods, updating saidone time period.
 7. A method of controlling display means in a radiocommunication terminal having the display means for displayinginformation corresponding to input of a user instruction, the displaymeans displaying information at selective first brightness and seconddisplay brightness lower than the first display brightness, comprising:the step of inputting a user instruction for setting the radiocommunication terminal to either one of first and second modes; the stepof setting the radio communication terminal to either one of the firstand second modes in accordance with the input, and outputting a modesetting output; and the control step of controlling the display means,the control step including causing the display means in the first modeto display information at the first display brightness during a firsttime period and at the second display brightness after a lapse of thefirst time period, and causing the display means in the second mode todisplay information at the first display brightness during a second timeperiod longer than the first time period and at the second displaybrightness after a lapse of the second time period.
 8. A methodaccording to claim 7 , further comprising the update step of, when a newuser input is supplied during the first and second time periods,updating the time periods.
 9. A method according to claim 7 , whereinthe first mode corresponds to a normal mode in which speech is madeusing the radio communication terminal, and the second mode correspondsto one of an information reception mode in which information is receivedvia a radio channel, a mail creation mode in which mail is created, anda mail browsing mode in which mail is browsed, and the control stepincludes setting the second time period when the second mode is set. 10.A method of controlling a terminal having a display section which candisplay information visible at one of a brightness mode and a darknessmode in response to a key input, comprising steps of: setting thebrightness mode to have a first time period in response to the keyinput; setting the brightness mode to have a second time period longerthan the first time period in response to a predetermined key input forsetting the terminal to have a predetermined function; maintaining thebrightness mode during the one of the first and second time periods,which is previously set; resetting the brightness mode to have the onetime period to continue the brightness mode during the one time period;and switching the brightness mode to the darkness mode after a lapse ofthe one time period, the first time period and second time period.
 11. Amethod according to claim 10 , wherein the predetermined functioncorresponds to one of a wireless application protocol mode fordisplaying data received from the outside of the terminal, and a mailmode for sending or receiving mail from the outside of the terminal.